An occasionally irregular blog about orthodontics

December’s Big Orthodontic Research Update: Part 1. Diagnostic records and methods of canine exposure

By on December 5, 2013 in Clinical Research, Research Methods with 1 Comment
December’s Big Orthodontic Research Update: Part 1. Diagnostic records and methods of canine exposure

December’s big  orthodontic research update: Part 1 Records and canines

Today it did not get properly light in Manchester, North of England and I have spent some time reading recent publications.  This is a busy time for publishing trials and systematic reviews and I have decided to divide this up into two blogs.  The first is going to be on whether it is possible to define a standard orthodontic dataset and the second is on the best method for exposure of palatally placed canines.  The Blog next week is going to be on the other two papers, one is a systematic review of bonding and the other a discussion on split mouth studies.  It will take me some time to write this one, as it is complex!  So lets have a look at the two papers for this week.

images-6Records needed for orthodontic diagnosis and treatment planning


Rischen R et al

Plos One: 2013: 8: 11: e74186

This paper was published in Plos One, which is a great open access journal. The authors should be congratulated for getting an ortho paper published here, as it is tough to get into this journal.

What did they want to find out?

They carried out this study to identify the  records that we should take for orthodontic patients and consider if it is possible to develop a core dataset.  In effect, they carried out a systematic review to identify the effects of records on treatment planning.  Their main inclusion criteria were studies that evaluated the effect of orthodontic records on treatment decisions which compared two types of records.

They adopted the usual systematic review methodology and carried out a quality assessment of the papers that they included.  They identified 17 studies that had the potential to be included in a meta analysis, however, they felt that the quality of the studies was low and it was not possible to carry out a quantitative meta analysis. Nevertheless, they did provide a qualitative interpretation of the findings of the four studies that were of higher quality.

They came to the following limited conclusions

Cephalograms are not routinely needed for Class II treatment planning

Digital models can replace plaster study casts

Cone beam CT may be indicated for the diagnosis of impacted canines.


But based on their findings

The minimum data set for orthodontics remains undefined

So what?

As with all papers that we read, it is necessary to answer the “so what” question, particularly with relevance to clinical practice

Firstly, I thought that it was very interesting that they concluded that cephalograms were not needed for Class II treatment.  It is important to point out that this conclusion was confined to Class II because the only studies that they could include investigated the effect of the cephalogram on treatment decisions for Class II cases.  I think that this finding is important.  Because if we consider that cephs are not needed for routine Class II cases, then we could consider that they are not needed for Class I cases. This is because of the likeliehood of a more limited skeletal discrepancy and less dento alveolar compensation.  I do not often take cephs for Class I cases and I now shall certainly re consider whether I need to take them for Class II cases.

It is good, in my opinion, that we can continue moving towards using 3D scans of models as opposed to plaster models.

It is also clear that CBCT, with its reduced dose, could help with the diagnosis of impacted canines, but importantly it should not be used routinely for all types of malocclusion.

When I first read this paper, I was a little disappointed because they could not come to firm conclusions on the ideal dataset. Nevertheless, when I looked at it more closely, I felt that it provided very useful information. Have a look at it, it is free and it could become required reading!


photo-2Palatally impacted canines: choice of surgical orthodontic treatment method does not influence post treatment periodontal status

Smailiene D et al

European Journal of Orthodontics: 2013: 35: 803-810

This is a paper from the EJO which is not open access, so you have to either be a member of a society or have access via a library that pays a subscription to the publisher, Oxford University Press.

Several blogs ago I reviewed a paper by Parkin et al in the August Clinical trials review and this continues our theme

This study was directed at finding out if there were differences in the periodontal health of palatally impacted canines which were exposed using a closed or an open procedure.

They took a sample of 43 patients with palatally impacted canines and allocated them to either open or closed exposures.  This was not a random allocation but was done by allocating every second patient to the open technique group.  As a result, it was not possible to ensure that the allocation was concealed from the operator and this places this investigation at high risk of bias.

The quality of this publication was then further compromised by the absence of a sample size calculation.

The outcome measures were periodontal health and bone support. They analysed the data with simple univariate statistics with multiple testing of many variables.

They concluded that there were no differences between the open and closed techniques. When I looked at the values they reported it was clear that any differences between the groups were small and not clinically significant.

What did I think?

This study has two main problems.  The first being the lack of concealment of treatment allocation and this makes it at high risk of bias.  Secondly, they did not carry out a sample size calculation and this means that they had no way of making sure that their finding arose because the sample sizes were too small and the study lacked power to detect a difference.

As a result, I am afraid  that this study does not really help us to decide which is the best way to expose a palatally impacted canine.

Robine J. Rischen,, K. Hero Breuning,, Ewald M. Bronkhorst,, & Anne Marie Kuijpers-Jagtman (2013). Records Needed for Orthodontic Diagnosis and Treatment Planning: A Systematic Review Plos One DOI: 0.1371/journal.pone.0074186

Dalia Smailiene,, Aiste Kavaliauskiene,, Ingrida Pacauskiene,, Egle Zasciurinskiene, & Krister Bjerklin (2013). Palatally impacted maxillary canines: choice of surgical-orthodontic treatment method does not influence post-treatment periodontal status. A controlled prospective study. European Journal of Orthodontics (35) DOI: 10.1093/ejo/cjs102

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  1. Bill Weekes says:

    Hi Kevin,

    I am going to stick my neck out. Perhaps you don’t need a Ceph for diagnosis of a Class II case, however, I would argue that a pre-treatment AND a pre-finishing Cone Beam CT are necessary for the proper TREATMENT of a Class II (even more – ANY) orthodontic case. Why? Well without pre-treatment and pre-finishing 3-D examinations you cannot tell exactly what effect that your treatment has had on the teeth and the alveolar structures. CBCT is the ONLY way to see the labial bone around the teeth (especially the lower incisors). I make decisions regarding the need for IPR based on what has happened to the labial bone during the course of the treatment (examination of labial bone influences my diagnosis and treatment planning pre-treatment also) I can exactly see how well my tip and torque has been achieved as well as assess the effect of growth. I am always finding that the pre-finishing CBCT indicates more finishing is needed. I am at the extreme end of the spectrum regarding the benefit of possible invasive records and I believe that the information is beneficial and worth the possible risk (what was the risk again?). Now to translate my anecdote into hard evidence…..

    Of course, there is more to say on the benefits of CBCT in diagnosis but space does not permit further discussion. Thanks for a stimulating and thought provoking blog.

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